The proposed study examines two psychological mechanisms hypothesized to underly the effectiveness of elctromyographic (EMG) biofeedback therapy. Forty-eight recurrent tension headache sufferers will be treated in a prospective outcome study in which the actual EMG feedback contingency and information about the clients success at the biofeedback task are independently manipulated in a 2 x 2 factorial design. This will allow us to determine the relative contribution of the actual feedback contingency and perceived success at the biofeedback task to improvement in tension headache activity. The relationship between measures of psychological learning (changes in self-efficacy and coping) and physiological learning (ability to control EMG activity) and tension headache improvement will be examined.